Because some of the island's Northern coastline is inaccessible, we needed another way to
measure the parts we couldn't visit. This is where trigonometry comes in.

First, you mark out a baseline on the ground that is as flat as possible. We needed a method of measuring angles, so we made a giant protractor. The angles were marked on it
using a folded circle of paper and a 10mm (about 0.4 in.) spanner (wrench) as a guide.